1. Field of the Invention
The invention relates to a stirring blade optimum for stirring a culture liquid for medicine and the like and a sealed stirring apparatus using the stirring blade.
2. Description of the Related Art
Conventional stirring blades and stirring apparatuses generate a liquid flow by rotating a stirring blade by rotating a motor or perform a stirring by moving a disc blade up and down at a large stroke.
However, in a culture liquid and the like in a field of medicine, a rotary stirring is not preferably because it damages fungus bodies, and further a stirring apparatus having a rotary sliding portion has a problem in that it is not preferable due to a problem of a contamination (pollution) of a culture liquid.
To prevent a leakage of a liquid to be stirred and its vapor from a stirring vessel and entering of foreign substances from the outside, Japanese Patent No. 4316251 granted to the applicant discloses a sealed stirring apparatus having a stirring vessel, an up/down movable diaphragm disposed on an upper surface portion of the stirring vessel so as to airtightly cover the upper surface portion, a rod member fixed and vertically disposed to the diaphragm so as to pass therethrough, a stirring blade fixed and vertically disposed to a lower end portion of the rod member, a baffle plate disposed on an inside surface of the stirring vessel in a longitudinal direction, and a plurality of flat plate blades for the stirring blade standing on upper and lower surfaces of a disc plate in an oblique radial state to generate a discharge flow in an obliquely radially external direction, wherein an inside of the stirring vessel is stirred by moving the stirring blade up and down.
Although the sealed stirring apparatus disclosed in Japanese Patent No. 4316251 forms a good swirling flow in the stirring vessel by an up/down reciprocating motion of the stirring blade, a flow in an up-down direction is not perfect.
Further, the conventional stirring blades, which perform a stirring by moving the disc blade up and down at the large stroke, have a problem from an operating viewpoint and a structural viewpoint (structure of a sealed portion) although they forcibly promote, mixing.
An object of the invention, which was made to overcome the above problems, is to provide a stirring blade preferable mainly to a stirring in fields of medicine and food and a stirring apparatus using the stirring blade, wherein the stirring blade has such a structure that a stirring liquid in a stirring vessel is not strongly subjected to a shearing action and is sufficiently mixed, dispersed, and homogenized by perfectly fluidizing the stirring liquid in an up/down direction and is prevented from being polluted.